i found it http://newflesh.org/about_us
Just a warning, but the above website contains "suggestive" material. Enter at your own risk.
Also, considering this website is also a bookstore, I'm inclined to believe you may have to purchase the image or something. I haven't found any info on that specific picture yet though.
EDIT:
I haven't found anything that specifically states the image is not usable, but I think you should've contacted the artist... if he wasn't dead.
It is with great sadness that I bring you the news of Robert North’s death on July 30th 2010.
He is survived by his wife Sarah, and his daughter Justine.
His books are no longer available through this web site.
His books are now available at:
http://stores.lulu.com/bobnorth
You'll have to find a way to contact the artist's wife, and as I look through the new site she has put up I'm becoming increasingly skeptical that she would let you use the image considering that it may be in one of those books. I suggest finding a new image.
Would this Stock Image work for you? (
http://www.sxc.hu/photo/1204250)